North Korea has disputed US President Donald Trump’s account of why the summit between Trump and Kim Jong Un collapsed, insisting the North demanded only partial sanctions relief in exchange for shutting down its main nuclear complex.

Trump, who was on his way back to Washington on Thursday, said talks broke down because Kim insisted that all the punishing sanctions the US has imposed on Pyongyang be lifted without the North committing to eliminate its nuclear arsenal.

“It was about the sanctions. They wanted sanctions to be lifted in their entirety and we couldn’t do that,” Trump told reporters at a press conference in Hanoi, after the summit ended early.

However, North Korean Foreign Minister Ri Yong Ho told a news conference held in Hanoi past midnight and hours after Trump left the Vietnemese capital that North Korea had sought only a partial lifting of sanctions and had offered a “realistic proposal”, including the dismantling of its main nuclear site at Yongbyon.

He said if Washington partially removed sanctions, North Korea could permanently end all nuclear material production, including plutonium and uranium, under US observation.

“This is the biggest denuclearisation step we can take based on the current level of trust between the two countries,” Ri said in a rare exchange between a North Korean official and reporters.

“In fact, as we take steps toward denuclearisation, the most important issue is security but we thought it would be more burdensome for the United States to take military-related measures, which is why we saw partial lifting of sanctions as corresponding action.”

Ri said the North was also ready to offer in writing a permanent halt of the country’s nuclear and intercontinental ballistic missile tests and that Washington wasted an opportunity that “may not come again”.

The North’s position wouldn’t change even if the US offers to resume another round of dialogue, he added.

The White House did not immediately respond to a request for comment on the minister’s remarks.

‘Walked away too soon’

“I think it was a substantive step forward that the North Korean leader Kim Jong Un was prepared to offer to dismantle the Yongbyong facility,” she said.

“As far as we understand, it isn’t the only facility. Now I would have expected Trump, in that situation, would have haggled over how many and what kind of sanctions should be lifted,” she added.

The United Nations and the US ratcheted up sanctions on North Korea when it conducted repeated nuclear and ballistic missile tests in 2017, cutting off its main sources of hard cash.

During Thursday’s summit, Trump and Kim cut short their talks, skipping a planned working lunch at the French-colonial-era Metropole hotel after a morning of meetings.

“Sometimes you have to walk, and this was just one of those times,” Trump told reporters in Hanoi, adding “it was a friendly walk”.

Failure to reach an agreement marks a setback for Trump, a self-styled dealmaker under pressure at home over his ties to Russia and testimony from Michael Cohen, his former personal lawyer who accused him of breaking the law while in office.

The collapse of the talks raised questions about the Trump administration’s preparations and about what some critics see as his cavalier style of personal diplomacy.

Meanwhile, there was disappointment and alarm in South Korea, which backs efforts to end confrontation on the Korean peninsula. Seoul said it regretted that no deal had been reached but the two sides had made progress.

Wang Yi, a senior Chinese diplomat, said difficulties in the talks were unavoidable but the two sides should press on and China would play a constructive role.

Japanese Prime Minister Shinzo Abe said he backed Trump’s decision and wanted a meeting with Kim.

There was no indication of when Trump and Kim, or their negotiators, might meet again.